#include<stdio.h>
#include<stdlib.h>
#include<windows.h>
int main()
{
    int i,j;
    int x=0;
    int y=5;
    int vx=1;
    int vy=1;
    int left=0;
    int right=20;
    int top=0;
    int bottom=10;
    while(1)
    {

        x=x+vx;
        y=y+vy;
        system("cls");
    for(i=0;i<x;i++)
        printf("\n");
    for(j=0;j<y;j++)
        printf(" ");
    printf("O\n");

    Sleep(50)
    if((x==top)||(x==bottom))
        {vx=-vx;
        printf("\a");
        }
    if((y==left)||(y==right))
        {vy=-vy;
        printf("\a");
        }

    }
    return 0;



}